This invention relates generally to clutch release type thrust bearings, and more particularly concerns a clutch release bearing which is adapted to permit radial realignment or adjustment of the bearing relative to a carrier sleeve on which it is mounted so as to accommodate some slight misalignment between the axis of a carrier sleeve upon which the bearing is mounting on the one hand and the axis of rotation of clutch release fingers against which the bearing engages on the other hand.
Automotive clutch throw-out or release bearings are used as a force-transmitting device between a foot-operated clutch pedal lever and clutch fingers. Generally speaking, the bearing comprises a thrust type of bearing adapted to transmit thrust forces from a non-rotating pedal lever mechanism to the rotating fingers of the clutch mechanism. The mass production of automotive clutches, clutch bearings and associated parts requires that these parts be manufactured and assembled at minimum cost. However, relatively high standards of quality and reliability must also be met in this process. To assure compatability of the mass produced parts, it is important that the parts be designed, arranged and/or assembled so as to reliably operate in spite of slight part misalignments which may occur during assembly. These misalignments can arise as a result of minor variations in part sizes and shapes, even though each part may be within manufacturing tolerances.
Such misalignments can also occur gradually over the service life of the vehicle, due to the substantial operating forces and occasional wear over long periods of use to which the parts are subjected. Exemplary clutch throw-out bearing assemblies are described for example in U.S. Pat. No. 3,909,086 and U.S. Pat. No. 4,046,436.
The bearing of the present invention is advantageously designed so as to permit some radial movement or displacement of the bearing relative to a radially stationary carrier sleeve member to which it is mounted. This radial movement accommodates a corresponding amount of radial misalignment which may occur between the axis of the carrier sleeve and the axis of rotation of the clutch fingers which the thrust face of the bearing is intended to engage. This assures proper engagement of the clutch fingers by the bearing thrust face.
Moreover, the bearing assembly of the present invention is advantageously designed so as to permit such radial movement or realignment of the bearing relative to the carrier sleeve only in response to radial forces applied thereto upon engagement with the clutch fingers. Once the proper axial alignment is achieved, the assembly of the invention provides for frictional engagement of the bearing which engagement tends to maintain the radial position or orientation of the bearing relative to the carrier sleeve in the absence of further force applied thereto in a radial direction. That is, the radial movement permitted the bearing does not result in a radially free bearing which might oscillate or wobble, but only permits movement as required for alignment with the clutch fingers, thereafter tending to maintain the bearing in the radial orientation appropriate for maintaining such alignment.
Further in this regard, the bearing of the invention may also be utilized with a constant running type of clutch arrangement which maintains a slight preloading of the clutch bearing relative to the clutch fingers. That is, the bearing thrust face is maintained in engagement with the clutch fingers for rotation therewith whenever the associated automotive engine is running.